Conventionally, in a timepiece including a wheel train which rotates by driving a motor, for example, in an analog electronic timepiece, a wheel train is rotated by driving a rotor constituting a step motor. For example, gear wheels such as a fifth wheel-and-pinion, a fourth wheel-and-pinion, a third wheel-and-pinion, and a minute indicator, constitute the wheel train. Rotor pinion (in a rotor this refers to parts other than the rotor magnet, and similarly hereunder), the fifth wheel-and-pinion, and the third wheel-and-pinion may be formed from a metal, or may be formed from a so-called engineering plastic such as polyacetal.
Moreover, conventionally, in a timepiece including a wheel train which rotates by the force of a mainspring, for example, in a mechanical timepiece, the wheel train is rotated by rotation of a barrel drum including mainsprings. For example, gear wheels such as a barrel complete, a second wheel-and-pinion, a third wheel-and-pinion, a fourth wheel-and-pinion, and an escape wheel-and-pinion constitute a wheel train. A gear wheel has a gear wheel section and a shaft section. A main plate, a wheel train bridge, and a second bridge are provided with bearing section. The shaft section of the gear wheel is rotatably supported by the bearing section. The third wheel-and-pinion and the fourth wheel-and-pinion may be formed from a metal, or may be formed from a so called engineering plastic such as polyacetal.
The main plate constitutes the substrate of the analog electronic timepiece and the mechanical timepiece. The wheel train bridge and the second bridge constitute the bearing members of the analog electronic timepiece and the mechanical timepiece. The main plate, the wheel train bridge, and the second bridge may be formed from a metal such as brass, or a so-called engineering plastic such as polycarbonate.
However, in a timepiece including plastic parts such as a rotor, a fifth wheel-and-pinion, a fourth wheel-and-pinion, and a third wheel-and-pinion formed from engineering plastics, in the case where the plastic parts are transported by a parts feeder, the plastic parts may become charged in some cases due to friction. Referring to FIG. 9, if a charged plastic part, for example a plastic rotor 876 is held by a metal chuck 880, the charged negative electrode (−) in the chuck 880 and the charged negative electrode (−) in the rotor 876 become mutually repulsive (or, the charged positive electrode (+) in the chuck 880 and the charged positive electrode (+) in the rotor 876 become mutually repulsive), so that the rotor 876 is likely to move or jump out in the direction of the arrow.
Referring to FIG. 10, a movement (machine body) 800 of the analog electronic timepiece includes a main plate 802 and a stator 874. In the movement (machine body) 800 of the analog electronic timepiece, if the charged rotor 876 is combined with the main plate 802, the charged positive electrode (+) in the main plate 802 and the charged positive electrode (+) in the rotor 876 become mutually repulsive (or, the charged negative electrode (−) in the main plate 802 and the charged negative electrode (−) in the rotor 876 become mutually repulsive), so that the rotor 876 is likely rise in the direction of the arrow and jump. As a result, the shaft section of the rotor 876 can not be located in a predetermined position. If the wheel train bridge 812 is combined with the main plate 802 in such condition, the shaft section of the rotor 876 may be bent, or the shaft section of the rotor 876 may be damaged.
Furthermore, referring to FIG. 11, when the charged rotor 876 is lubricated with lubricating oil (chronometer oil: shown by hatching in FIG. 11) using a lubricating unit 888, if the lubricating unit 888 becomes close to the charged rotor 876, the non-conductive lubricating oil becomes polarized and charged. Therefore, there is the likelihood of the droplets of the lubricating oil being not only adhered to the parts of the rotor 876 requiring the lubricating oil, for example, the shaft in FIG. 11, but also being dispersed and adhered to the unnecessary parts, for example, the pinion section other than the shaft section of the rotor 876 or the like.
Therefore, heretofore there is a problem in that antistatic agent must be sprayed on the plastic parts such as the rotor pinion, the fifth wheel-and-pinion, the fourth wheel-and-pinion and the third wheel-and-pinion. Moreover it has heretofore been necessary to earth to the various parts manufacturing machines or assembling machines